Herd immunity

Viral Tweet Opposing ‘Herd Immunity’ Gets Pretty Much Everything Wrong

In a recent viral tweet, the anti-Brexit campaigner Jolyon Maugham criticised the Government’s initial Covid strategy (which, as we know, was later ditched in favour of lockdowns).

I’m no defender of the Government’s response to the pandemic, but it’s hard to imagine a more wrong-headed criticism than this. Indeed, it’s impressive how many fallacies Maugham managed to pack into 280 characters.

First: “Herd immunity”. As the authors of the Great Barrington Declaration have tirelessly pointed out, describing any response to the pandemic as a ‘herd immunity strategy’ is like describing a pilot’s plan to land a plane as a ‘gravity strategy’. Given that Covid cannot be eliminated, herd immunity will eventually be reached, regardless of what we do.

The goal of any plan to address Covid, write Kulldorff and Bhattacharya, “should be to minimise disease mortality and the collateral harms from the plan itself, while managing the build-up of immunity in the population.”

Second, the implication of Maugham’s tweet is that the Government’s initial strategy was motivated by Conservative ideology, and that the alternative – lockdown – is what’s backed by science.  

Yet, as I and others have pointed out, it’s actually lockdown that deviates substantially from the pre-Covid consensus. Indeed, the UK’s pandemic preparedness plan does not even mention the term. And in 2019, the WHO classified “quarantine of exposed individuals” as “not recommended under any circumstances”.  

Given that the first lockdown was implemented by a communist one-party state, and that subsequent lockdowns were imposed with almost no prior discussion, it would make more sense to say lockdown was motivated by ideology.

Third, the virus does not “target” working class and poorer people, while leaving Etonians and bankers unscathed. It is not some pathogenic agent of class warfare.

If “target” is taken to mean “infect”, then the virus targets people who aren’t immune to it. And if “target” is taken to mean “kill”, then it would be most accurate to say the virus targets the old and the immunocompromised. After all, these groups account for the overwhelming majority of deaths.

Now, it’s true that death rates have been higher in working class occupations, as I noted in a previous post. But this is far more plausibly due to lockdown than to the Government’s initial strategy, which was in any case abandoned in March of 2020.

As the art critic J. J. Charlesworth quipped, “There was never any lockdown. There was just middle-class people hiding while working-class people brought them things.” Middle-class people like Jolyon Maugham, I might add.

COVID-19 Vaccination and the Death of Informed Consent

by George Santayana

Informed consent is one of the cornerstones of modern medicine and the foundation of the patient/doctor relationship. The principle of informed consent is a core part of the Nuremberg Code on human research ethics and states that consent for any medical treatment must come from the patient themselves who needs to understand both the benefits and risks. Likewise, the opposite, which we might call “informed refusal”, is just as important and a patient can refuse treatment or withdraw consent at any time.

The “informed’ part of informed consent can occur in a number of ways such as provision of written materials (the piece of paper you throw away when you open a packet of headache tablets) or a discussion with your doctor. Regardless, the information given to a patient needs to be accurate, balanced and cover both the benefits and risks.

Consent must also be given freely and without undue influence or coercion. Of course, a clinician can express their opinion and offer advice as to what course of action a patient might take, but ultimately the decision to proceed (swallow the pill, take the test, have the operation) resides with the patient.

Informed consent places the individual patient at the heart of clinical practice and given that they are the person receiving the treatment and taking any associated risks that intrinsically feels like the right thing. And so it used to be for vaccinations, where it was up to the individual whether they wished to have a specific vaccination or not. Yes, there were some specific situations where vaccination was deemed necessary (e.g. travelling to certain regions of the world) but in these situations the focus was on protecting the individual themselves. But then COVID-19 came along and suddenly this patient-centred view of the world was replaced by governments and the mainstream media with one where a treatment benefit was not just to the individual receiving the treatment but also to society… a change, which as I will discuss here, inexorably leads to the destruction of informed consent.

To understand why, let’s start by considering the benefit of a vaccination to an individual.

One of the peculiar things about vaccines as treatments is that their benefit is not the same as their effectiveness. This is because a vaccine works by generating immune “memory” of a specific pathogen. The effectiveness of the vaccine is therefore dictated by how good the immune response is to the immunisation and what type of immune memory it creates. The effectiveness is also to some extent dictated by the pathogen itself. So, for a virus like smallpox, vaccination was highly effective not least because the pathogen proved unable to evolve to evade vaccine induced immunity. In contrast, the parasites that cause malaria or sleeping sickness have evolved mechanisms to evade the immune system and so vaccinations against these pathogens have proven to be highly elusive. SARS-CoV-2 sits somewhere in the middle in that it appears susceptible to immunity from vaccination but can mutate and evolve variants that might be able to overcome this immunity.

However, having immune memory is of no benefit to the patient per se. The benefit to the patient only comes if, subsequent to vaccination, they become infected with the pathogen. At this point, because of the immune memory created by the vaccination, they raise a more robust, rapid and effective immune response, meaning that they will either not become ill, or if they do become ill, it will be with a milder form of the disease. In other words, infection by the pathogen is a pre-requisite of gaining the benefit from the vaccination, a benefit that only occurs if, in the absence of the vaccination, they would have developed significant disease. Vaccination is therefore a lot like insurance; you gain no benefit from having the insurance policy documents sitting in your filing cabinet; they only become useful when the thing you are insuring against actually happens.

This benefit of vaccination is captured in the concept of “number needed to vaccinate” or NNTV (i.e., how many individuals need to receive a vaccination in order for one of them to avoid developing serious disease). NNTV is therefore driven by two things: the prevalence of the pathogen within a population and the severity of the disease caused if someone was to be infected by the pathogen. The NNTV is why we don’t routinely vaccinate individuals against diseases such as yellow fever that are not prevalent in the U.K. and why we focus flu vaccinations on vulnerable individuals for whom the disease carries significant risk.

For SARS-CoV-2 and COVID-19, the seriousness of the disease is largely age related, meaning that the NNTV is also age-related. As a result, we might only need to vaccinate a few hundred over-60s for one to avoid having a serious case of COVID-19 while we would need to vaccinate thousands (if not tens or hundreds of thousands) of the under-20s to achieve the same outcome.

Unlike the benefit, the safety risks associated with SARS-CoV-2 vaccinations are not age dependent and include rare, serious adverse events including death. So, the balance of benefit and risk for their use also varies with age and is vastly different for a diabetic man in his 60s compared to a healthy young woman in her 20s. From the perspective of the benefit to the individual, there is therefore no way we should be considering vaccinating healthy young people using these vaccines. The likelihood of serious adverse effects may be small but then so is the likelihood of avoiding serious COVID-19 and so there is a very real possibility that a mass vaccination campaign of young people will produce more harm than benefit. In fact, the original strategy was to focus COVID-19 vaccinations on the over-50s for precisely this benefit/risk reason.

But somewhere along the way, COVID-19 vaccinations stopped being solely about the benefit to the individual and started to be about the benefit to society (i.e., the goal of achieving herd immunity). A brief reminder: herd immunity occurs when a sufficient proportion of a population is immune to a given pathogen in such a way that the likelihood of encountering an infectious person drops, as does the likelihood of an infectious person being able to pass the infection on to another individual who also becomes infectious. As a result, herd immunity protects individuals who are naïve to an infection simply because they are unlikely to ever encounter an infectious person and at the same time it means that an infection can no longer spread effectively through the population and may even die out.

Vaccinations can produce herd immunity and in the case of smallpox were so effective that they led to the elimination of the disease itself. But from an informed consent perspective there is one huge difference between vaccination campaigns that have historically produced herd immunity and that being pursued for COVID-19 and that is that historically the diseases concerned were of significant risk to those receiving the vaccination. For example, measles is a significant risk for young children and so we vaccinate young children. But young children often grow up to be adults and carry their measles immunity with them and so, as a result, measles herd immunity emerges as a consequence of measles vaccination… it is absolutely not its aim.

Achieving herd immunity is also when vaccine effectiveness comes into play, and this is because the vaccine must not only reduce the individual’s likelihood of developing serious disease but also produce “neutralising” immunity in the sense that infected, immune individuals are not infectious to others. As a result, the inclusion of “benefit to society” as a consideration for vaccinations against SARS-CoV-2 raises the bar as to what an effective vaccine looks like and it is becoming clear that the current Covid vaccinations almost certainly don’t jump over that bar. However, important as they are, I don’t want to focus on these technical aspects but instead come back to what the “benefit to society” addendum to vaccine benefit means for informed consent.

As soon as we aim to achieve herd immunity through vaccination, then we need to ensure that a sufficient proportion of the entire population are vaccinated. As discussed above, this happens naturally as a consequence of some vaccinations against childhood diseases but for SARS-CoV-2 and COVID-19 the benefit is to the more elderly population and not children and young people. As a result, to achieve herd immunity we need to vaccinate individuals who will receive minimal benefit from the treatment itself. We could treat this as a form of medical altruism and say, “We know that you won’t benefit personally, but for the good of society please have this treatment.” If we were to use this as the point of persuasion for individuals to have the vaccination, then this would not necessarily be a problem; people give blood as an altruistic act for the medical benefit of others all the time and encouraging them to do so isn’t unethical. However, it becomes an issue in this case because you need lots of young people (and the population in general) to be vaccinated in order to cross the magic threshold for herd immunity and purely relying on a sense of community or selflessness may not be sufficient to achieve the levels of vaccination required to achieve this societal benefit. So, to tackle this problem, and to use a horrendous Americanism, the population need to be incentivised to be vaccinated.

Let’s be completely clear: whatever form these incentives take they are coercion, and so utterly contrary to the principle of informed consent. This would be bad enough if the vaccinations were completely safe, but the fact that they carry even the small possibility of serious and even life-threatening risks makes this coercion even more egregious. Effectively, the benefit to the patient is no longer confined to the treatment itself, but whether they might win a prize, or be able to travel, or go to a nightclub, or watch a football match. Informed consent has been lost in a haze of rewards for the vaccinated.

Unfortunately, it gets worse. This is because it is a relatively simple logical step to move from seeing unvaccinated refuseniks as individuals to be cajoled or bribed into being vaccinated to treating them as a threat to the herd-immunity-through-vaccination project. Once we’ve taken this step, then the unvaccinated become hazards to the vaccinated; immune dementors who could suck the immunity from the rest of the population… or more specifically, variant factories whose every breath carries the risk of a new mutant virus able to evade vaccine-induced immunity.

Once we classify unvaccinated individuals as hazards, we can then deploy versions of the ‘passive smoking argument’ to move beyond coercion and into compulsion. Essentially the argument runs like this: we know that you as an (unvaccinated) individual have rights, but your (in)actions are also a hazard to broader (vaccinated) society and so we need to balance your rights as an (unvaccinated) individual with the rights of your fellow (vaccinated) citizens and as a result we must, reluctantly, remove your rights in order to protect the broader rights of others. This argument creates the necessary backdrop for policies to compel vaccination because it legitimises the removal of individual consent as a necessary evil to protect the broader (vaccinated) population.

However, unlike smoking in public, being unvaccinated is not something that can be switched on or off and so the only way to ensure that the unvaccinated hazard is contained is to separate it from the vaccinated population, which naturally leads to concepts such as vaccine passports and ‘No Jab, No Job’ policies. Voluntary fun activities like going to the pub or having a meal out – normal day-to-day existence – become harder and harder for those not having the vaccine, leaving many people with no choice but to take the medicine regardless of how they feel about it. And without choice how can there be consent?

They say that the road to hell is paved with good intentions, and so I believe it is with the Government’s COVID-19 vaccination policy. What starts out as a noble ambition to use COVID-19 vaccination as a tool to achieve a broader benefit to the population, logically ends up in the destruction of informed consent and the creation of medical apartheid. This is the inevitable consequence of shifting the focus of a medical treatment from the individual to broader society. It is also the thin end of a very unpleasant wedge because once we allow the principle that the state can have a direct stake in what is in the best interest of an individual’s health then where do we stop? Arguments that “the others” are a medical hazard to “us” have been deployed to justify some of the worse abuses of modern times and although I am absolutely not saying that current policies amount to anything like this, the resonance here should make even the most ardent proponent of vaccine compulsion uncomfortable. History teaches us that when governments, rather than individuals, decide on what is the best medical treatment this almost always leads to dire consequences – often for some of the most vulnerable in society. But with vaccine passports and NHS apps, it certainly feels like we’ve already started down this road and regardless of your views on COVID-19 vaccinations we should all be very worried about where this journey might lead.

George Santayana is the pseudonym of a senior executive in a U.K. pharmaceutical company.

Vaccines Don’t Stop Transmission and Won’t Give Us Herd Immunity, So Let’s Stop Mass Testing, Experts Tell MPs

A panel of experts has told MPs that there is no way of stopping Covid from spreading through the entire population because the vaccines don’t prevent infection and transmission, especially given the Delta variant, adding that we should stop worrying about community testing. “What matters is the burden of patient hospitalisation and critical care,” says a Consultant Paediatrician at Imperial College Healthcare NHS Trust. “And actually there hasn’t been as much with this Delta variant.” The Telegraph has more.

Scientists said it was time to accept that there was no way of stopping the virus spreading through the entire population, and monitoring people with mild symptoms was no longer helpful.

Professor Andrew Pollard, who led the Oxford vaccine team, said it was clear that the Delta variant could infect people who had been vaccinated, which made herd immunity impossible to reach even with high vaccine uptake. …

Speaking to the All-Party Parliamentary Group on Covid, Sir Andrew said: “Anyone who is still unvaccinated will, at some point, meet the virus. 

“We don’t have anything that will stop transmission, so I think we are in a situation where herd immunity is not a possibility and I suspect the virus will throw up a new variant that is even better at infecting vaccinated individuals.”

Until recently, it was hoped that increasing the number of Britons jabbed would create a ring of protection around the population. As late as last week, the Joint Committee on Vaccination and Immunisation said one of the reasons it had advised that 16 and 17 year-olds should be vaccinated was because it may help prevent a winter Covid wave.

However, analysis by Public Health England has shown that when vaccinated people catch the virus they have a similar viral load to unvaccinated individuals and may be as infectious.

Paul Hunter, Professor in Medicine at the University of East Anglia and an expert in infectious diseases, told the Committee: “The concept of herd immunity is unachievable because we know the infection will spread in unvaccinated populations and the latest data is suggesting that two doses is probably only 50% protective against infection.”

Professor Hunter, who advises the World Health Organisation on Covid, also said it was time to change the way the data was collected and recorded as the virus became endemic.

“We need to start moving away from just reporting infections, or just reporting positive cases admitted to hospital, to actually start reporting the number of people who are ill because of Covid,” he added. “Otherwise we are going to be frightening ourselves with very high numbers that actually don’t translate into disease burden.”

On Tuesday, Sajid Javid, the Health Secretary, confirmed that third dose booster shots would be given from next month. However, Sir Andrew argued that, if mass testing was not stopped, Britain could be in a situation of continually vaccinating the population.

“I think as we look at the adult population going forward, if we continue to chase community testing and are worried about those results, we’re going to end up in a situation where we’re constantly boosting to try and deal with something which is not manageable,” he said.

“It needs to be moving to clinically driven testing in which people are willing to get tested and treated and managed, rather than lots of community testing. If someone is unwell they should be tested, but for their contacts, if they’re not unwell then it makes sense for them to be in school and being educated.”

Worth reading in full.

What the Modellers Still Don’t Understand About Herd Immunity

Bristol’s Professor Philip Thomas has a new piece in the Spectator this week. Readers may recall that I criticised his previous pieces for what seemed in my view to be wildly over-the-top predictions of the likely scale of the Delta surge.

In June, he predicted “an enormous final wave“, in which the virus “would quickly seek out the one-in-three Britons who are still susceptible: mainly the not-yet-vaccinated” and peak in the middle of July (the bit he got right) “at anywhere between two million and four million active infections“. According to the ONS, around 951,700 people in the U.K. were PCR positive in the week ending July 24th, and that appears to be the peak, which is less than half of Professor Thomas’s lower estimate.

He now admits: “The situation is better than I bargained for at the beginning of June and also better than my estimates a month later.” In fact, it’s so much better, that he thinks “the decline in active infections can only mean that England is about to reach the herd immunity threshold for the Delta variant”. By which he means that “around 86% of England’s adults and children must now be immune”. On this basis he argues that it is “extremely unlikely” that there will be a new Covid surge in the coming winter.

The problem with this analysis is it is still based on the SAGE assumption that herd immunity is a once-for-all-time thing, that was made harder to reach by the more transmissible Delta variant, but which we have now just achieved, mostly through vaccination, and it will now keep us safe.

America’s Delta Surge

New Covid infections are surging in America, driven by the Delta variant. The states which reopened in the spring, such as Texas, Mississippi and Georgia, and defied the predictions of catastrophic exit waves, are now seeing surges. Florida, too, which reopened last autumn, is seeing a spike in infections, and hospital admissions are rising.

Reuters takes a look at how states are responding – which is by doing remarkably little, with the appetite for restrictions even in Blue states now that the vaccines are rolled out seemingly much lower than in previous outbreaks.

Since the 8th of March, There Have Been 9,484 *Fewer* Deaths Than Normal

Today the ONS announced that there were 8,808 deaths in England and Wales in the week ending 2nd July 2021. This is 118 more than the previous week, but still 5.2% below the five-year average. Here’s the chart from the ONS:

Deaths in England and Wales have now been below the five-year average for 14 of the past 17 weeks. Over that time, there were 9,484 fewer deaths than you’d expect based on the average of the last five years. And recall that, due to population ageing, the five-year average understates the expected number of deaths. Hence the true level of “negative excess mortality” is even greater.

The number of deaths registered in the week ending July 2nd was below the five-year average in seven out of nine English regions. (Only the North East and North West saw positive excess deaths.) Compared to the five-year average, weekly deaths were 10.7% lower in the East of England, and a remarkable 12.1% lower in the South East.

The fact that “negative excess mortality” has now persisted for three consecutive months supports the hypothesis that deaths were “brought forward” by the pandemic.

It’s been widely noted that the link between cases and deaths has weakened substantially in recent weeks, thanks to the build up of population immunity. Although the number of daily infections has surpassed 20,000, the number of daily deaths remains in the low double digits. However, the situation is actually even more positive: measured by excess deaths, the pandemic hasn’t taken any lives since early March.

The Outbreak Point: Are Covid Outbreaks Triggered When the Viral Load in the Air Hits a Certain Threshold?

In recent posts I’ve been exploring the question of why COVID-19 (much like other seasonal viruses) has a Jekyll and Hyde-like nature, being puny for much of the year then exploding in short, sharp outbreaks for a few weeks at a time, usually though not exclusively in the winter. I argued in a post last week that seasonality appears to be driven largely by cycles in the human immune system (though there may be environmental factors such as UV radiation, temperature and humidity as well). The trigger for the somewhat irregular (and not necessarily winter) outbreaks appears to be the appearance of a new variant (or virus) that is able to infect slightly more people, amounting to just one in 18 additional people when estimated from the secondary attack rate. The end of the outbreaks then corresponds to the exhaustion of the small pool of newly susceptible people and the restoration of the temporarily disturbed herd immunity.

I noted that the difference between a surge and a decline amounted only to a small absolute change in the R growth rate, from 1.3 during a surge to 0.8 during a decline, and that the shift between these rates often occurs very abruptly. This means that infected people quite suddenly start infecting 1.3 other people before, around three and a half weeks later, just as suddenly switching back to infecting just 0.8 people. This change in R is reflected in a similar change in the secondary attack rate (the proportion of contacts an infected person infects), which varies between around 15% during surges to around 10% outside of them. I observed that this difference is small enough to be explained by a slightly increased susceptibility to a new variant and a subsequent restoration of herd immunity a short time later.

After writing this it occurred to me that with such a subtle trigger it would seem that outbreaks should be highly sensitive to the amount of social contact people have with one another, and thus to the imposing and lifting of restrictions (or to voluntary social distancing). Indeed, it is logic like this which presumably explains why SAGE members and other scientists persist in believing in the efficacy of lockdowns regardless of how much data emerges showing they don’t make any significant impact on the infection or death rate.

A recent set of SAGE minutes explains the logic of restrictions:

Professor Tim Spector Calls for Vaccination of Children ‘Because Delta Variant’

King’s College London Professor of Genetics Tim Spector dismayed many of his Twitter followers yesterday by calling for the vaccination of older children. The reason? Because the Delta (Indian) variant means we now need 85% of the population vaccinated to reach herd immunity, he claims.

Professor Spector, who leads the ZOE Covid symptom study, was replying on Twitter to Israeli scientist Eran Segal, who tweeted: “Before Delta, Israel reached herd immunity or close to it. To regain herd immunity, we need to vaccinate as many of the 1.2 million over the age of 12 who have not yet been vaccinated.”

Spector wrote: “In the U.K. with delta we need to get near 85% of the population – which also means vaccinating older children.”

In calling for this, Prof Spector appears not to be concerned about the worries of many scientists including members of the JCVI about the benefit-versus-risk balance for teenagers in having the vaccine, or the ethics of suggesting children should be given a vaccine with no long-term safety data not for their own benefit but for the benefit of others.

The notion that a threshold of herd immunity will only be reached if 85% of the population is vaccinated also bears no relationship to real-world data. It’s not entirely clear what Segal and Spector mean by herd immunity in these tweets, but if they mean that without an 85% vaccination rate the Delta variant will continue indefinitely to cause mass hospitalisations and deaths, then perhaps they would like to explain why India’s test positivity rate entered a sustained plummet nearly two months ago, despite the Delta variant being dominant and the country at that point having only 2.5% of its population fully vaccinated? (The figure now stands scarcely higher at 4.3%.)

Does This Explain Why COVID-19 is Normally so Puny But Occasionally Goes Bang?

I wanted to come back to the question of what causes COVID-19 occasionally to have explosive outbreaks. We’ve had two in England so far. Using the graph below (produced by Imperial’s REACT study using symptom-onset reports from their antibody survey, so no PCR tests involved) we can see when they occurred. The first occurred from around February 25th to March 19th 2020, ending after about three and a half weeks, as abruptly as it began. The second got going around December 2nd, and ended – once again abruptly after three and a half weeks – on December 25th. As the lines below indicate, these starts and stops bear no relation to when lockdowns were imposed or lifted (the red and blue lines respectively).

Given that (as we can see) Covid was around in England throughout the winter of 2019-20 (arriving in November according to this graph) and was also simmering away in the autumn of 2020 without taking off, a key question is what triggers the beginning and end of the more explosive outbreaks?

Another way of putting the same question is: why does COVID-19 occasionally, Jekyll and Hyde-like, transform from a relatively gentle, not very infectious disease into a super-infectious disease for a few weeks, before suddenly returning once more to its largely benign form?

Perhaps surprisingly, Covid in England has only been in ‘Hyde’ form for about seven weeks in total so far, with the R rate (the speed at which the epidemic is growing) only going significantly above one (indicating an exponentially growing epidemic) for around three and a half weeks in February/March 2020 and three and a half weeks in December 2020. The rest of the time it’s been up and down in different regions, particularly in the autumn, but there’s been no nationwide surge. What, then, on those two occasions triggered the disease to become briefly so much more infectious across the country?

“The NHS is Going to be Smashed in Weeks”, Cummings’s Data Geek Told Boris – on the Day Infections Peaked in London

Lockdown Sceptics‘ readers have had their fill of Dominic Cummings stories in the last 24 hours. However, his claim, repeated yesterday in front of MPs, that without a lockdown last March “the NHS is going to be smashed in weeks” cannot go unanswered.

These are the words that, according to Cummings, data analyst Ben Warner said to Boris Johnson when he confronted him with “evidence” on Friday March 13th 2020 that a lockdown was necessary to prevent the NHS being imminently overwhelmed.

March 12th and 13th 2020 are notable for being the days when various Government advisers did the media rounds to sell to the public the idea of “building up some kind of herd immunity“, as Chief Scientific Adviser Sir Patrick Vallance put it on Radio 4’s Today programme. Prior to this, the Government had been sticking to the script of their action plan and pandemic preparedness strategy that did not talk about herd immunity (even if it implied it) but about mitigation of the impact of the disease.

Whose idea it was to start talking about building up herd immunity by infection is not clear, and, despite pontificating for seven hours yesterday, Dominic Cummings did not enlighten us on that point. The move was, however, disastrous for Government public relations, as the concept jarred with the public. Worse, it was criticised by scientists and health care professionals, who argued that herd immunity through infection was not a sound policy aim even if it would be the inevitable result of the mitigation strategy. Dr Adam Kucharski from the London School of Hygiene and Tropical Medicine put the matter succinctly on Twitter: